Impact of new diagnostic criteria of diabetes mellitus.

Abstract

To compare the frequency of diabetic individuals diagnosed by fasting plasma glucose (FPG) > or = 7.0 mmol/L with previous value i.e. > or = 7.8 mmol/L and to determine the diagnostic accuracy of FPG > or = 7.0 mmol/L. A cross-sectional study. The Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi, from April to July 2003. FPG of 5250 subjects was checked to compare the frequency of diabetic subjects diagnosed by FPG > or = 7.0 mmol/L with > or = 7.8 mmol/L. Of them, 301 symptom-free subjects were subjected to 75 g Oral Glucose Tolerance Test (OGTT) and their 2 hours post glucose (2-h PG) challenge level was taken as "gold standard" to determine the diagnostic accuracy of FPG at > or = 7.0 mmol/L. By lowering the cut off point of FPG from 7.8 mmol/L to 7.0 mmol/L, the percentage of diagnosed diabetic subjects increased from 35% to 42%. Statistical analysis revealed a significant increase (p < 0.0001). FPG > or = 7.0 mmol/L had a diagnostic sensitivity of 70%, specificity 91%, the predictive value of positive and negative diagnosis was 84% and 80% respectively. FPG at cut off point of >7.0 mmol/L, will greatly facilitate the early diagnosis of diabetes mellitus (DM). An early diagnosis can be further facilitated by a combination of FPG and 2-h PG estimation.